The clock symbolizes time, which feels unpredictable and sped-up throughout the play. It feels that way for a reason: Shakespeare has in fact compressed fourteen years worth of history into the span of a month. At the start of the play, Richard seems to work the sped-up time to his favor, successfully wooing Anne as soon as her husband has died and passing off his murder of Clarence as the too-quick fulfillment of King Edward's own death-order. Yet, as the play goes on, Richard seems to lose control of time and frequently asks what time it is. Before the final battle, a clock strikes, the sun fails to rise at its scheduled time, and Richard fears the resultant black sky bodes ill for his fate on the battlefield. Indeed, he is killed by Richmond, which brings the hurtling play to a sudden halt.